FIGURE 2.

S₂ (A) and S₃ (B) state lifetime decay curves for wild type Arabidopsis and psbo1 mutant thylakoids under different ionic conditions. The time axis indicates time of dark incubation at 24 °C. ▪, wild type decay curve under control ionic conditions (10 mm chloride with no added calcium); •, psbo1 control; ♦, psbo1 + 150 mm NaCl; ▴, psbo1 + 20 mm CaCl₂ + 50 μm ionomycin (n = 4–13; error bars are ±1 S.E.). In some instances, the symbols are larger than the error bars. Treatment of wild type thylakoids with either 150 mm NaCl or 20 mm CaCl₂ + 50 μm ionomycin had little effect on the S state lifetimes or other parameters examined in this study and are not shown.